Quick overnight stops in route

We do not, because we always plan a max driving distance of 6 hours. This provides lots of wiggle room to make side excursions and on-the-spot site seeing or if a road side attraction grabs our attention. We plan 6 hours of drive time and stay in actual campgrounds, even if just over night. We also enjoy exploring new campgrounds and enjoy meeting other RVers there too. It really provides a safe, comfortable, and restful night of sleep. Of course, we incorporate the drive in our plans. The "journey" is just is important as the "destination". Maybe even more. So we don't rush and drive for hours on-end and arrive exhausted and beat out. We use to do that when the kids were little, and it ended up being no fun, because everyone arrive at the destination with all these plans, and ended up, the first day there, we were all so tired and grouchy, no one enjoyed anything, except arguing with each other and everyone grumpy. So when the kids no longer camped with us, as they got older, we shifted the way we travel and camp. But with kids, especially when they are young, it IS all about the destination.

But to answer the OP's question, we've pull into grocery store parking lots a few times and caught a few hours. And we've stayed in a couple church parking lots too. (we had a prior "OK" from the pastor, and left a donation for them too).